Turbine wheel and bucket mounting



L. A. DARLING. TURBINE WHEEL ANDBUCKET MOUNTING.

APPLICATION HLED MAR. 4. 1919.

INVENTOR: Lewis 17. Darli Patented Jan. 18, 1921.

BY Z

A TTORNEY5 UNITED STATES PATENT OFFICE.

LEWIS A. DARLING, OF PHILADELPHIA PENNSYLVANIA; ASSIGNOR TO ELECTRIC SERVICE SUPPLIES COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA.

TURBINE WHEEL AND BUCKET MOUNTING.

Application filed. March 4, 1919.

To all whom it may concern Be it known that I, LEWIS A. DARLING, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have in vented certain new and useful Improvements in Turbine Wheels and Bucket Mountings, of which the following is a spool-- lication, reference being had to the accompanying drawings.

My invention relates both to turbine buckets or blades and the adjacent parts, including the means for mounting and securing the buckets in position, and also to the construction of the turbine wheel. or rotor as a whole.

The main objects of my invention are stability and permanency of the structure, simplicity of assembly and general economy of manufacture. Other advantages obtainable in connection with the invention will appear from the description hereinafter of the best embodiment at present knownto me, while its scope will be indicated in my claims. It will be understood, in particular, that while I have illustrated and described an elastic fluid turbine structure, the in vention is applicable in connection with turbines of other than the elastic fluid type, and to the mounting of stationary buckets or guide blades as well as moving ones.

In the drawings, Figure I, represents a partial side view of an elastic fluid turbine wheel embodying my invention, certain parts appearing in brolizen-away section.

Fig. II, shows an axial section at a surface corresponding to the line II-II, in Fig. I, on an enlarged scale.

Fig. III, is a fragmentary edge VIGW, of the wheel without the buckets; it also shows a subjacent part of one bucket member and a part which in practice overlies the wheel edge, displaced from that position to expose the wheel edge. p v

Fig. IV, comprises four views of a bucket member, showing internal face and side elevations and top and, bottom views.

Fig. V, is a fragmentary sectional view of one 5f the wheel parts, at a surface corresponding to the line VV, of Fig. III.

Fig. VI, is an inverted plan view of a modified form of bucket.

Referring first to Figs. I, II, and III, it will be seen that the wheel has a main body Specification of Letters Patent.

Patented Jan. 18, 1921.

Serial No. 280,563.

portion with a plurality of buckets 1, at its periphery. The main body of the wheel comprises a central hub 2, with a shouldered peripheral flange 3, shaft opening; a web formed by a pairof disk or plate members 4 and 5, securedat opposite sides otthe hub flange 3, by rivets 6; and a peripheral bucket-carrying rim element 7, carried by the web. As shown, the outer edge portion of each of the plates t and 5, is cupped or bent over to form an integral laterally extending flange or rim member 8, and the edge of each flange 8, has a plurality of notches 9. The hub flange 3, has a couple of screw threaded holes 10, which are freely exposed by notching of the plate 5, at 11, and afford a convenient means for removing the wheel from its shaft.

As will be. seen from Figs. I and II, the

buckets '1, abut endwise against. the rim element 7, of the wheel, and each ofthem has at its abutting end securing means 12, whereby it is held against the rim. As shown in Figs. I, II, and IV, thesecuring means 12, has a shank 13, that lies in the notches 9, of the rim members 8, 8, and an enlarged head 14, thatengages said memhers at their inner sides. Preferably, the rim members 8, 8, are machined on both inner and outer faces (or otherwise given smooth, t rue surfaces and made of accurately uniform thickness), so as to fit the spaces between the bucket ends and the heads 14, easily but snugly and hold the buckets without substantial end play, On the other ends of the buckets 1, is a shroud or cover member 15, which cooperates with the rim 8, to form the usual inclosed curved channels or passes between the buckets.

This rim member 15, need not necessarily be in sections, but may consist of a single unitary strip or band. As shown, it has a plurality of holes 16, (see Fig. III) adapted to fit on upstanding projections 01' lugs 17, (see Figs. I and II) on the corresponding ends of the buckets 1, and is secured by the heading over of the lug ends, as at 18.

I'Vhile turning of the buckets 1, with ref erence to the rim element 7, can be prevented in various ways, I prefer to do this by antiturning engagement means embodied in the securing means 12. For the sake of economy and a conical in manufacture and for other reasons, it is H plates 4 and 5, that lie at right angles to the rim ,members 8, 8,. immediately subjacent thereto,such'engagement of the head 14, at eitherside sufiicing to positively prevent turning of the bucket 1. As shown in Fig. V, the inside of this angle-wise extension 20, of each rim member 8,.for such it is in reference to the-bucket mounting function of the rim,is machined or otherwise given a smooth, true engaging surface. To insure proper correlation of the parts generally,

I and,-in particular,.to make certain that the heads 14, will be properly held between the rim; member extensions 20, without unde-.

sirable angular play, it may be advisable to finish the edges of said rim members and of the notches 9, in a similar way.

The.foregoing description of the bucket member 1, with its securing means 12, and lug 17 at opposite. ends of the acting portion jor bucket proper, tacitly assumes that this member iis made'of one single, integral piece o;f,metal-. This mode of construction is, indeed,"preferable; and it will be seen that if the rivet lug 17, and cover holes 16, be round (as shown in Figs. III and IV), it is possih ble to make theffinished bucket member from a blankof ordinary or suitable bucket crosssection by two simple operations: a turning operation in which the head 14, is undercut and the shank- 13, and lug 17, formed, and a.

" milling operation in which both flanks of the head portion are cut away to form the flat sides 19, 19. Or, if preferred, a lateral pressing-operation can be substituted for a milling operation, and the head-1 L of the 1 securing means ofLthe bucket member given the. modified-form shown in Fig. VI at 23. Besides its functional features, therefore, the bucket member. 1, shown affords great 1 practical advantages in respect to its own manufacture. V r v In the assemblage of the wheel, it is preferable first to rivet all the buckets 1, to the cover members 15, by their lugs 17, then to put the buckets in place on the plate memher 4, forexlample, and then to put the plate member 5, in place and secure both plate members to the hub 2, by the rivets 6. The plate members 4 and 5, are also preferably secured together'neartheir peripheries by a {plurality of rivets 9.1, spacing sleeves 22, about the rivets allowing them to be spun or otherwisejheaded ovenwithout distortion of the plate members. It will be seen that in the completed wheel each plate member serves,-iirst, through 1ts rim member S.

proper, and secondly, through its rim extenkeeps the securing means 12, in elfective anti-turning engagement with said other rim member.

If the inner surfaces of the rim members 8, be slightly inclined, as shown in Fig. V, at 24, the buckets will be tightly gripped and'wedged when the plates 5, are secured together.

From the foregoing description, it will be seen that my invention affords great simplicity of construction combined with strength, rigidity, and lightness; also, that it is applicable with special advantages to very small turbines.

Having thus described my invention. 1 claim:

1. In a turbine wheel, the combination of a hub, a disk, or plate, secured to said hub and having a peripheral edgewise notched flange or rim extending laterally therefrom. a plurality of buckets abutting endwise against said rim, each of said buckets l :ving at its abutting end securing means coin-- prising a round shank in one of the rim notches and a head engaging the rim memher to hold the bucket endwise thercagainst. and another disk or plate secured to said hub and to the first mentioned plate and serving to keep the bucket shanks in the notches, said buckets being kept from turning solely by lateral engagement of their heads with the central web portion of one of said plates. 2. A turbine bucket mounting comprising, in combinatioma rim mounting member with multi-notched edge, a plurality of buckets abutting endwise against said rim member, each of said buckets having at its abutting end securing means comprising a round shank in one of the rim notches-and a head engaging the rim member to hold the bucket endwise thereagainst, and an other mounting member secured to saidrim member and serving to keep the bucket shanks in the notches, said buckets being kept from turning solely by lateral engagement of their heads with said other mounting member. 3. Aturbine bucket mounting comprising, in combination, a plurality of rim mounting-members with their adjacent edges coincidently notched; a plurality of buckets abutting endwise against said rim members. each of said buckets having at its abutting end securing means romplising a round shank in one of the holes formed by said rim notches and a head flattened on opposite sides engaging the rim members to hold the bucket endwise thereagainst, and said rim ltl Ell

members having portions extending at an angle to those against which the buckets abut between which the buckets are held so as to be prevented from turning.

45. An integral, unitary turbine bucket provided with securing-means at its rimabutting end, comprising a round shank projecting from its abutting surface and an enlarged head on said shank.

5. A turbine bucket in accordance with claim 4. wherein the head has a that side.

6. A turbine bucket in accordance with claim 4 wherein the head has substantially parallel opposed flat sides.

7. An integral unitary, turbine bucket formed of a blank of a uniform cross section, and having, at its rim-abutting end, securing means comprising a round shank projecting from its abutting surface, and an enlarged laterally flattened head on said shank consisting of a portion of the aforesaid blank.

8. A turbine bucket mounting comprising, in combination, a rim mounting-member with multi-notched edge; a plurality of integral buckets abutting endwise against said rim member, each of said buckets having at its abutting end securing means comprising a round shank in one of the rim notches and a laterally flattened head formed of a portion of the bucket originally of the same cross section with the rest, en gaging the rim members to hold the bucket endwise thereagainst, and another mounting member secured to said rim member and serving to keep the buckets in the notches; one of said rim members extending at an angle to said rim mounting member and engaging with the flat sides of the bucket heads so as to prevent them from turning.

9. In a turbine wheel, the combination of a plurality of plates having peripheral edgewise notched flanges extending laterally therefrom, each of said flanges being of wedge-shaped cross section; and a plurality of buckets abutting endwise against said flanges, each of said buckets having at its abutting end securing-means comprising a shank engaged in one of the notches of each member and a head engaging said member to hold the bucket endwise thereagainst; said plates being secured together so as to grip the bucket heads tightly by wedge 51( tion of their flanges.

In testimony whereof I have hereunto signed my name at Philadelphia, Pennsyl- Vania, this first day of March, 1919.

LEWIS A. DARLING.

Witnesses:

J AMES H. BELL, E. L. FULLERTON. 

